1. Field of the Invention
This invention relates to display systems, and more particularly to computer display systems performing navigation or zooming (i.e., magnification) in response to user input.
2. Description of Related Art
Several different types of input devices allow for controlling a displayed image based upon manual user input. Examples of such input devices include conventional keyboards and pointing devices such as a mouse. Most input devices require a certain degree of manual dexterity. Physically challenged users (e.g., users without hands, or with permanent or temporary loss of motor skills) may have difficulty operating keyboards and conventional pointing devices.
A user may also be “situationally” challenged by virtue of simultaneously performing another task. Examples of situationally challenged users include a doctor operating on a patient and someone driving a car or operating machinery.
Other known types of input devices allowing hands free control of a displayed image include speech-to-text converters. Various types of head tracking technologies also exist for controlling displayed images dependent upon movement of a user's head.
“Zooming” is the term generally used to describe magnification of a portion of display data (e.g., an image). To “zoom in” is to increase magnification, and to “zoom out” is to decrease magnification. It would be desirable to have an alternate system and method providing hands free control of a displayed image, especially for zooming.